Device for Detachably Fixing a Holder for a Doctor Blade in a Paper Production Plant

ABSTRACT

A device for the detachable fixing of the holder for a doctor blade, which is assigned to a supporting and guiding roll in a paper production plant, to a support. The holder is mounted on the support such that it can be pivoted about an axis oriented at least approximately in the direction of the doctor edge bearing on the supporting or guiding roll. Furthermore, the holder is formed by holding fingers which extend transversely with respect to the pivot axis and which are in each case constructed with a first bearing part which interacts with a second bearing part located on the support and also, between the holder and the support, there being at least one actuating element, by way of which the holding fingers can be pivoted independently of one another. One of the two bearing parts is formed by a bearing shell, which is formed with a cutout, in particular with a slot, extending in the direction of the pivot axis, and the other of the two bearing parts is formed by a bearing pin which is carried by a web or the like penetrating the cutout in the bearing shell. Accordingly, the holder can be displaced with respect to the support in the direction of the pivot axis over the entire length of the doctor blade.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. § 119, of Austrian application A 1944/2006, filed Nov. 23, 2006; the prior application is herewith incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a device for detachably fixing a holder for a doctor blade, which is assigned to a supporting and guiding roll in a paper production plant, to a support. The holder is mounted on the support such that it can be pivoted about an axis oriented at least approximately in the direction of the doctor edge bearing on the supporting or guiding roll. Furthermore, the holder is formed by holding fingers which extend transversely with respect to the pivot axis and which are in each case constructed with a first bearing part which interacts with a second bearing part located on the support and, between the holder and the support, there is disposed at least one actuating element, by means of which the holding fingers can be pivoted independently of one another.

In paper production plants there is a wire, which is moved along the plant on supporting or guiding rolls and to which the paper stock or pulp is applied. In the direction of movement of the wire, the liquid contained in the paper stock is sucked out of the latter and the paper web produced as a result is dried by means of air sucked through the wire. In the further course of the movement path of the paper web in this plant there is a felt, on which the paper web is dried further. Both the wire and the felt are moved over supporting and guiding rolls. Further on, the paper web is moved directly over supporting and guiding rolls.

On account of the liquid sucked out of the paper stock and on account of the drying operations, constituent parts, in particular pulp fibers, led out of the paper stock or out of the paper web reach the supporting or guiding rolls, which means that the latter become contaminated. Since these contaminants impair the operation of the supporting or guiding rolls, there is the need to subject them to continuous cleaning. For this purpose, the supporting and guiding rolls are in each case assigned a doctor blade, which is brought into contact with the relevant supporting and guiding roll and by means of which contaminants located on the roll are doctored off the latter.

Here, there is the need to arrange the doctor blade in such a way that it bears on the relevant roll with a predefined pressure. For this purpose, the holder of the doctor blade is constructed with a device for adjusting the angular position of the doctor blade with respect to the relevant roll. Since, moreover, the holder of the doctor blade often has to be replaced in order to be able to clean the latter and the doctor blade, there is also the need to construct the fixing of the holder for the doctor blade to the support for the holder in such a way that it can be released in the simplest possible way.

In prior art devices of this type, the holder for the doctor blade and the support of the holder are constructed with lugs projecting toward one other, which are formed with drilled holes assigned to one another, into which a bearing pin extending over the width of the wire is inserted. In order to be able to remove the holder for the doctor blade from the support for the holder, the bearing pin is pulled out laterally. In this way, the holder for the doctor blade can be removed from the support, that is to say lifted off, transversely with respect to the longitudinal direction of the bearing pin. In this case, however, there is often the difficulty that, on account of the constructional configuration of the plant, the space required for a movement of the holder transversely with respect to its support is not available.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a device for releasably fixing a holder for the doctor blade in a paper production plant which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which is further developed in such a way that the holder for the doctor blade can be displaced with respect to the support in the longitudinal direction of the bearing pin without needing to be moved from the carrier, that is to say lifted off the latter, transversely with respect to the insertion direction.

With the foregoing and other objects in view there is provided, in accordance with the invention, an assembly for mounting a doctor blade assigned to a supporting and guiding roll in a paper production plant, comprising:

a support and a holder for carrying the doctor blade detachably mounted to the support and pivotally mounted on the support about a pivot n axis oriented substantially in a direction of a doctor blade edge bearing on the supporting or guiding roll;

the holder being formed by a plurality of holding fingers extending transversely with respect to the pivot axis and each having a first bearing part interacting with a second bearing part on the support;

at least one actuating element disposed between the holder and the support for pivoting the holding fingers independently of one another;

one of the first and second bearing parts being formed by a bearing shell having a cutout formed therein, extending in the direction of the pivot axis, and the other of the first and second bearing parts being formed by a bearing pin carried by a web penetrating the cutout in the bearing shell, enabling the holder to be displaceable with respect to the support in the direction of the pivot axis over an entire length of the doctor blade.

In other words, the objects of the invention are achieved in that one of the two bearing parts is formed by a bearing shell, which is formed with a cutout, in particular with a slot, extending in the direction of the pivot axis, and the other bearing part is formed by a bearing pin which is carried by a web or the like penetrating the cutout in the bearing shell, which means that the holder can be displaced with respect to the support in the direction of the pivot axis over the entire length of the doctor blade.

Preferably, each holding finger is formed with a separate bearing part, whereas the bearing part located on the support extends in one piece over the entire length of the doctor blade or is formed by individual sections of the bearing part located at a distance from one another. In particular, each holding finger is assigned a bearing pin, which is fixed to the holding finger by means of a web or the like, and on the support there is provided a strip-like bearing shell extending over the length of the doctor blade, or a plurality of sections of the strip-like bearing shell are provided, the at least one bearing shell being formed with cutouts, in particular with slots, on its side assigned to the holding fingers.

Preferably, a covering plate extending over all the holding fingers is also provided, is fixed to the holding fingers and bears on the edge of the doctor blade assigned to the holder. Furthermore, at their end assigned to the doctor blade, the holding fingers can be formed with profiling used for the fixing of the doctor blade. In particular, at their end assigned to the doctor blade, the holding fingers are each formed with a cutout, into which a strip projecting from the doctor blade can be inserted.

According to further preferred features, the holding fingers are formed as two-armed levers, which are mounted on the support in their central region, and the support for the holding fingers is constructed with a flexible covering element reaching over the holding fingers.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in device for the detachable fixing of a holder for a doctor blade in a paper production plant, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a side view of a device according to the invention;

FIG. 2 is a perspective view of the novel device on an enlarged scale as compared with FIG. 1;

FIG. 3 is a perspective view of some constituent parts of the device according to FIG. 1 on a reduced scale as compared with FIG. 2; and

FIGS. 4, 4 a and 4 b are three separate perspective views illustrating the mounting of a constituent part of the device according to FIG. 1 on an enlarged scale as compared with the other figures.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is illustrated a supporting and guiding roll 1, which is located in a paper production plant, underneath the wire, underneath the felt, or underneath the paper web. The roll 1 is assigned a doctor blade 2, which can be brought into contact with the surface of the roll 1. The orientation of the blade 2 is in a direction opposite to the direction of rotation of the roll 1. By means of the doctor blade 2, contaminants on the surface of the roll 1, which are caused by the dewatering of the paper stock on the wire or by the drying of the paper web, are removed.

The doctor blade 2 is fixed to a holder 3, which is formed by a large number of holding fingers 31 arranged beside one another and a covering plate 32 located above these. For this purpose, at its edge facing the holder 3, the doctor blade 2 is formed with a strip 21 which projects into cutouts 33 provided at the ends of the holding fingers 31. Furthermore, by means of the covering plate 32, which is screwed to the holding fingers 31, all the holding fingers 31 are connected to one another to form a single structural unit.

The holder 3 for the doctor blade 2 can be pivoted with respect to a support 5 for the holder 3 by means of a bearing 4 on the support 5. In order to adjust the pivoted position of the holder 3 with respect to the support 5, between the support 5 and the holder 3 there are two actuating elements in the form of inflatable hoses 6, by means of which the angular position of the holder 3 with respect to the support 5 can be adjusted.

In addition, at the ends of the holder 3 and of the support 5 that face away from the doctor blade 2, a flexible covering element 51 is provided.

The support 5 is located on a swinging arm 7, which is fixed to a shaft 8 which extends in the axial direction of the roll 1 and which can be adjusted into a pivoted position by means of a tensioning rod 9 and can be fixed in this position.

FIG. 2 reveals the doctor blade 2, the holder 3 for the doctor blade 2 with one of the holding fingers 31 and the covering plate 32, the bearing 4 for the holder 2 on the support 5, the actuating elements 6 and the covering element 51.

FIG. 3 illustrates the support 5 with the holding fingers 31 mounted on the latter and the actuating elements 6. As this reveals, over the length of the support 5 there are provided a large number of holding fingers 31 located beside one another, each holding finger 31 being formed with a bearing pin 41. The bearing pins 41 are mounted in bearing shells 42 fixed to the support 5. As this illustration further reveals, each bearing pin 41 can be assigned a separate bearing shell 42 or a plurality of bearing pins 41 can be assigned a common bearing shell 42. In addition, the cutouts 33 in the holding fingers 31 can be seen.

As can be seen further from FIGS. 4, 4 a and 4 b, the bearing pins 41 located on the holding fingers 31 are fixed to the holding fingers 31 by means of a web 41 a in each case. Furthermore, the bearing pins 41 are assigned bearing shells 42 which are fixed to the support 5 and which, on their side facing the holding finger 31, are formed with a slot 42 a. In this case, the clear width of the slot 42 a is somewhat greater than the thickness of the webs 41 a. On account of this formation of the bearing 4, the holding fingers 31 can be displaced freely with respect to the support 5 in the axial direction of the bearing pins 41. As a result, the holder 3 with the holding fingers 31 and covering plate 32 and at the same time with the doctor blade 2 can be detached from the support 5 by being displaced axially with respect to the latter, without being removed from the latter transversely with respect to the axis of the bearing pins 41, that is to say lifted off the latter. In this way, the need to be able to remove the holder 3 for the doctor blade 2 from the support 5 for the holder 3 is met even if there is no space available to lift the holder 3 off the support 5. 

1. An assembly for mounting a doctor blade assigned to a supporting and guiding roll in a paper production plant, comprising: a support and a holder for carrying the doctor blade detachably mounted to said support and pivotally mounted on said support about a pivot n axis oriented substantially in a direction of a doctor blade edge bearing on the supporting or guiding roll; said holder being formed by a plurality of holding fingers extending transversely with respect to the pivot axis and each having a first bearing part interacting with a second bearing part on said support; at least one actuating element disposed between said holder and said support for pivoting said holding fingers independently of one another; one of said first and second bearing parts being formed by a bearing shell having a cutout formed therein, extending in the direction of said pivot axis, and the other of said first and second bearing parts being formed by a bearing pin carried by a web penetrating said cutout in said bearing shell, enabling said holder to be displaceable with respect to said support in the direction of said pivot axis over an entire length of the doctor blade.
 2. The assembly according to claim 1, wherein said cutout in said bearing shell is a slot.
 3. The assembly according to claim 1, wherein each said holding finger is formed with a separate said bearing part, while said bearing part on the support extends in one piece over an entire length of the doctor blade.
 4. The assembly according to claim 1, wherein each said holding finger is formed with a separate said bearing part, while said bearing part on the support extends in individual sections formed at a distance from one another.
 5. The assembly according to claim 1, wherein each said holding finger is assigned a bearing pin that is fixed to said holding finger by way of a web, and wherein a strip-shaped bearing shell is disposed on the support said bearing shell extending over a length of the doctor blade and having a plurality of cutouts formed therein on a side assigned to the holding fingers.
 6. The assembly according to claim 5, wherein said cutouts are slots formed in said bearing shell.
 7. The assembly according to claim 1, wherein each said holding finger is assigned a bearing pin that is fixed to said holding finger by way of a web, and wherein a plurality of strip-shaped bearing shell sections are disposed on the support, said bearing shells having cutouts formed therein on a side assigned to the holding fingers.
 8. The assembly according to claim 7, wherein said cutouts are slots formed in said bearing shells.
 9. The assembly according to claim 1, which comprises a covering plate extending over all of said holding fingers, said covering plate being fixed to said holding fingers and bearing on an edge of the doctor blade assigned to the holder.
 10. The assembly according to claim 1, wherein, at an end thereof assigned to the doctor blade, said holding fingers are formed with profiling for fixing the doctor blade.
 11. The assembly according to claim 10, wherein, at the end assigned to the doctor blade, each said holding finger is formed with a cutout, into which a strip projecting from the doctor blade is inserted.
 12. The assembly according to claim 1, wherein said holding fingers are two-armed levers having a central region mounted on the support.
 13. The assembly according to claim 1, wherein the support for said holding fingers includes a flexible covering element reaching over said holding fingers. 